From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E736D3ECBE4; Fri, 9 Oct 2026 18:44:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791571499; cv=none; b=gThBHbH4U+Th/gqwpevI+kLY5vmjqOCS702yD4ODmxZmxnYuT634yM7J22Cb3njUdBUPWtgt3AFxBcuQrdlQ8rYc4riGPgaOZ+LJzSRhfGYDtU9EMQQcUQLhz8hLoe02vGajfs0+BU2/FeUXppZXRSdINj9VthOGptCiV29UK9k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791571499; c=relaxed/simple; bh=ocrMeNkMQZu7lUW0ZX/nXGH/6NYNDpKamVvMXgsOpXg=; h=Message-ID:From:Subject:To:Cc:In-Reply-To:References:Content-Type: Date; b=CJ8eA3Vyt6ssKgMVNFST+vu1oEW/Y6c+B3MaQCMGLeEHdHKtZfOn87LmOXSDWpNupSNU3/CuY5KiYq4kj1oTMUnwOwtVmLRAX5mVvXClP0CLugAxAU5LrDhcRbC3gdO1g/SCx4eIyNncQRKs10S3GnA1riBqOt8hRvBtqU4PsWM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=HvNJBZy9; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="HvNJBZy9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2E99B1F000FF; Fri, 9 Oct 2026 18:44:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791571498; bh=ocrMeNkMQZu7lUW0ZX/nXGH/6NYNDpKamVvMXgsOpXg=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=HvNJBZy9Tsu7oES9CdsfR4f/4C+IE4xqTb5dLbuMSUyzbZsJ/yjMXR+167f3p//XP ob9okM/QutTRXss9bRhSy32e9t+A72Lx1PrRuFf2/GmmRAXiVDVbwzemFvMgRSZxYa mGBdpo12ahOey7dmJZEFs/eqKDPFLTw8kz22QIdmMIpU+qXV5ZLU0U9IUSkRL5i3rL OIqQh4UappTglas5pgF9N8JI7YpuUHe0ZFJNh7EvC7+IM75vMMXflYmgSLcwMErzNk 4EiUwDS9kMlOCoyBbclPjMXyO/PYSmG2FK5aCTN1dnk9a11R8DFOwhl0lX7LvS5qgh DL5Mh9PLzrdVQ== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v5 17/38] scsi: sg: convert mmap hook to mmap_prepare and rework Reply-To: sashiko-reviews@lists.linux.dev To: =?utf-8?b?TG9yZW56byBTdG9ha2VzIChBUk0p?= Cc: bpf@vger.kernel.org, kvmarm@lists.linux.dev, "Vasily Gorbik" , linux-perf-users@vger.kernel.org, kvm@vger.kernel.org, linux-s390@vger.kernel.org, linux-usb@vger.kernel.org, "Marc Zyngier" , linux-rdma@vger.kernel.org, selinux@vger.kernel.org, "Heiko Carstens" , dri-devel@lists.freedesktop.org, "Oliver Upton" , "Christian Borntraeger" , linux-trace-kernel@vger.kernel.org, "Alexander Gordeev" , linux-scsi@vger.kernel.org In-Reply-To: <20261009-b4-mmap-prepare-vma-flag-sanify-v5-17-923b70125b1e@kernel.org> References: <20261009-b4-mmap-prepare-vma-flag-sanify-v5-0-923b70125b1e@kernel.org> <20261009-b4-mmap-prepare-vma-flag-sanify-v5-17-923b70125b1e@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Fri, 09 Oct 2026 18:44:56 +0000 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: > Move from the deprecated mmap hook to the new mmap_prepare hook. >=20 > We are mapping kernel pages here, so use the discontiguous kernel mapping > mmap action to do so. >=20 > Unwind the rather confusing loop and instead map as many pages as we can = at > one time. >=20 > Note that we do not need to pay attention to rsv_schp->k_use_sg here, as > the pages are populated for the length of the buffer at > rsv_schp->page_order granularity as compound pages. >=20 > The discontiguous kernel page mapping logic handles the compound pages for > us. >=20 > sfp->mmap_called keeps the buffer stable for us. As before it is never > cleared, so a failed mmap also leaves it set. >=20 > We also remove some useless vma, vma->vm_file NULL checks - these will > always be non-NULL if you reached the mmap hook logic. >=20 > We retain log output for consistency, but change what's output on page > mapping to indicate that sg_discontig_get() does the work now. >=20 > Note that we drop the VMA_IO_BIT flag for the VMA here. It was never > necessary as we invoke alloc_pages() which gives us refcounted folios that > are fine for GUP to access (VMA_IO_BIT would prevent that). >=20 > Reviewed-by: Suren Baghdasaryan > Signed-off-by: Lorenzo Stoakes (ARM) Sashiko has reviewed this patch and found no issues. It looks great! --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261009-b4-mmap-pr= epare-vma-flag-sanify-v5-0-923b70125b1e@kernel.org?part=3D17